An air-cored solenoid with length $30 \; cm$,area of cross-section $25 \; cm^{2}$ and number of turns $500$,carries a current of $2.5 \; A$. The current is suddenly switched off in a brief time of $10^{-3} \; s$. How much is the average back $emf$ induced (in $V$) across the ends of the open switch in the circuit? Ignore the variation in magnetic field near the ends of the solenoid.

  • A
    $2.5$
  • B
    $6.5$
  • C
    $9.2$
  • D
    $11.6$

Explore More

Similar Questions

The dimensions of self or mutual inductance are given as

The unit of inductance is

The self-inductance $L$ of a solenoid of length $\lambda$ and area of cross-section $A$ with a fixed number of turns $N$ increases as

$A$ graph of magnetic flux $(\phi)$ versus current $(I)$ is shown for four inductors $P, Q, R, S$. The largest value of self-inductance is for inductor:

$A$ solenoid is connected to a battery so that a steady current flows through it. If an iron core is inserted into the solenoid,the current will

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo